Solution Properties
Solution ID:
223924250031213
Last Modified Date:
Tue Aug 13 19:37:02 UTC 2024
Taxonomy Path:
Category//Performance//Product
Author:
legacyauthor
How do I use the Windows PING command to troubleshoot network connectivity or slowness?
Description
Cause
Resolution

 

[BCB:3:Network warning:ECB]

To use the Windows "Ping" command

  1. Click the Windows Start button.  Select Run.  In the Open cell, type CMD
  2. Click OK. The Windows Command Prompt screen will display.
  3. In the command prompt window, type: ping "computer name"This is the computer name or hostname of the target machine. For example, if you are a workstation called Workstation1, and the computer name of the server is SBS2008, type "Ping SBS2008" in the Windows Command Prompt screen.
    • To identify the computer name of a Windows-based computer, right-click This PC (or My Computer) and select Properties.
  4. Press Enter to initiate the ping.
    • You should receive 4 replies from the target machine, showing the target IP address. Verify this is the correct IP address that is replying by doing the following:
      1. Make a note of this IP address and log into the target machine as an administrator.
      2. Open the Command Prompt.
      3. In the Command Prompt window, type: ipconfig /all
      4. Press Enter. You may have to scroll up to see all the information.
        • You may see multiple network adapters. The correct one generally shows up at the top of the list and is usually titled Ethernet adapter Local Area Connection (although it can be different). A computer having two network interface cards (NICs) can cause problems for applications when it has two IP addresses. Disable the unused NIC if possible. Check with your IT person if you are unsure.
      5. Make a note of the IPv4 Address. This number should match the ping replies. If everything matches, you have network connectivity from the originating machine.
    • If you receive replies with a high time = ms (milliseconds) number (i.e. time=159ms), this is a sign of performance issues. If two computers are located in the same building, expected ping response times should be less than 1 millisecond (abbreviated and shown in the ping test as time< 1 ms). If you receive a response time even as small as time=5ms in an internal network, this is considered high and will impact network performance.
    • If you ping by hostname and receive "Request timed out" messages, and the IP address returned is correct, this usually means the target machine has a firewall running. Turn off all firewalls on the target machine and try the ping test again.
    • If you ping by hostname and receive "Request timed out" messages, and the IP address returned does not match the target machine's expected IP address, or you receive a reply from an IP address that does not match the target machine's IP address, or if you receive an "unknown host" error message, one of the following me be true:
      • The DNS cache on the originating machine (the one you're doing the ping from) may be invalid. Clear the DNS caches on the originating machine by doing the following:
        1. Open a command prompt window.
        2. Type ipconfig /flushdns
        3. Press the Enter key. This will force the originating machine to obtain new DNS information from its assigned DNS servers. If this is the cause of the problem, the effect will be immediate. If you attempt the ping test again, it should resolve correctly.
      • DNS servers may not be resolving name resolution for the target machine. Have IT verify this.
      • The network setting on the originating machine may be incorrect, such as invalid DNS servers being assigned, or incorrect static IP settings. Have IT verify this.
  5. After performing a ping test from the first machine to the second machine, you will need to run the same test(s) from the second machine to the first machine. Two-way communication is required for full network connectivity. Do not skip this step.

 NOTE: 

Some products may require that the fully qualified domain name (FDQN) be resolved. An FQDN is something such as abcserver.company.com. The server name or hostname would be abcserver. Pinging by IP address alone without ever pinging by hostname is not a good practice. Pinging by IP address does not identify domain name resolution and other issues. Pinging by IP address is only useful when used in conjunction with pinging by hostname or the FQDN.

For example, if you ping by hostname/FQDN and receive a "Destination host unreachable" or "Request timed out" and you ping by IP address and you receive replies with the correct IP address, you've just verified that most likely the target machine does not have a firewall running (hence it can reply to your ping request). However, DNS cache or DNS servers or some other factor may be the root cause of the "Destination host unreachable" error. Pinging by IP address alone will verify if there's potentially a firewall or not, or if the IP address exists. However, you cannot verify DNS resolution or other issues when pinging by IP address alone. If all tests are done correctly (i.e. pinging by hostname, ipconfig/all, checking for firewalls, etc.), you don't rarely need to ping by IP address.

[BCB:154:Chat 100 Contractor US:ECB]

 

 

 

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